The present inventive subject matter relates to information storage devices and methods of operating the same, and, more particularly, to information storage devices using magnetic domain wall movement and methods of operating the same.
In general, examples of conventional nonvolatile information storage devices in which recorded information is retained even when power is cut off include hard disk drives (HDDs) and nonvolatile random access memories (NVRAMs).
An HDD is an information storage device having a rotating part that may wear down over time. If the rotating part of an HDD wears down, an operational failure is likely to occur, thereby lowering the reliability of the HDD. A representative example of a non-volatile RAM is flash memory, which has come into widespread use. However, flash memory generally has relatively slow reading and writing speeds, a relatively short life span, and relatively small storage capacity when compared to an HDD. Flash memories may also have relatively high manufacturing costs.
To solve the problems of such conventional non-volatile information storage devices, new information storage devices that use the principle of magnetic domain wall movement of a magnetic material (hereinafter referred to as “magnetic track memory”) have been developed. In these magnetic information storage devices, a minute magnetic region formed of a ferromagnetic substance is referred to as a magnetic domain and a boundary portion between magnetic domains having different magnetization directions is referred to as a magnetic domain wall. The magnetic domains and the magnetic domain walls may be moved by applying current to a magnetic layer. An information storage device using magnetic domain wall movement detects a desired location by moving a domain of a nanowire magnetic track and writes data to or reads data from the detected location.